含气泡液体流动的剪切雷诺应力研究  

ON SHEAR REYNOLDS STRESS IN LIQUID FLOW WITH BUBBLES

作　　者：许兆峰[1] 罗锐[1] 杨献勇[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《工程力学》2005年第3期63-67,51,共6页Engineering Mechanics

摘　　要：含气泡液体流动的雷诺应力主要是由气泡存在及液体湍动而引起的,它们分别在层流和湍流流动中占主导地位。通过对粘性流体绕球形颗粒的流场进行研究,运用单元系综平均方法推导出由气泡引起的剪切雷诺应力关系式,并根据Sato(1981)的方法获得最佳剪切雷诺应力系数。此关系式与雷诺数的平方根成正比,且仅适用于空泡率较小的含气泡液体流动。通过模型预测及与Sato(1981)所得关系式进行比较,显示同意所得关系式更具有理论性,更合理。Reynolds stresses in liquid flow with bubbles are made up of two parts: a part induced by bubble displacement and a part produced by liquid turbulence. They are the main geneses of Reynolds stresses respectively in laminar flow and in turbulent flow. In this paper, approximate velocity expressions of uniform viscous liquid passing a sphere bubble are given, and a new formula of shear Reynolds stress induced by bubbles is derived using cell-ensemble average. The formula is in proportion to the square root of Reynolds number, and valid for low void fraction condition. By the method of Sato (1981), the best valid shear Reynolds stress coefficient is acquired. The new formula and that of Sato are compared. It is shown that the new formula is more reasonable.

关 键 词：两相流 泡状流 单元系综平均 雷诺应力 速度脉动 

分 类 号：O35[理学—流体力学]